NCT02449590

Onion, Cardiovascular Risk Markers and Gene Expression

The Effects of Onion on Plasma Lipoproteins, Blood Pressure and Gene Expression in Overweight Humans - a Double-blinded, Randomized Cross-over Study

• Status: Completed
• Phase: N/A
• Study type: Interventional
• Enrollment: 10 (actual)
• Sponsor: Professor Lars Ove Dragsted · Academic / Other
• Sex: All
• Age: 18 Years – 70 Years
• Healthy volunteers: Accepted

Summary

AIMS: The aims are to investigate whether: * Increased intake of onion (powder) affects plasma lipid profile, blood pressure, indices of insulin sensitivity and blood coagulation. * Increased intake of onion (powder) affects the expression/activity of enzymes in the defence against foreign substances, e.g. reactive oxygen species, and whether polymorphisms in some of the involved genes may modulate the effect. * Polymorphisms involved in the metabolism/effect of bioactive components in onion modulate the excretion of metabolites or modulate some of the outcome variables in the study. Other aims are to try to identify biomarkers for onion consumption in plasma, urine and feces and to investigate whether onion affects the secretion of fat and bile acids. HYPOTHESES: The investigators hypothesize that: * 2 weeks of increased onion intake will improve the plasma lipid profile * 2 weeks of increased onion intake will increase the metabolism of potentially harmful substances (such as ROS and free radicals) through a change in the expression or activity of certain enzymes. * That these effects are modulated by common gene variants (polymorphisms)

Detailed description

In a randomized controlled crossover design, participants will receive 2 daily meals with or without onion powder for 2 weeks. Between the two 2-week period is a 4-week wash-out period. One week before and during each intervention period, the participants will be instructed to avoid consumption of onion, garlic and all foodstuffs containing the same bioactive components (polyphenols, sulfur-molecules)as in onion. This includes a number of vegetables and fruits, condiments, tea, chocolate, red wine etc. Fasting blood samples will be drawn before and after (on 2 separate days) each intervention period, where also weight and blood pressure are measured. Participants will collect 24-hour urine and feces samples twice before and at completion of each intervention period. After the fasting blood sampling on the first blood sampling day in each period, participants will receive a test meal (with 10 g onion powder or placebo, i.e. 8.5 g sucrose+ 2 g soy protein isolate). The acute effects will be studied by blood sampling and urine sampling 0, 2, 4 and 24 hours after the test meal.

Conditions

• Blood Pressure
• Coagulation Delay

Interventions

Type	Name	Description
DIETARY_SUPPLEMENT	Onion powder	Hot meals with onion powder; 10 g/day onion powder corresponding to 100 g/day fresh onion in meals with potato and beef Intervention period 14 days.
DIETARY_SUPPLEMENT	Placebo	Hot meals without onion powder; Control meal with potato, beef, soy protein, and sucrose to match macronutrient composition of active treatment

Timeline

• Start date: 2008-08-01
• Primary completion: 2008-11-01
• Completion: 2009-04-01
• First posted: 2015-05-20
• Last updated: 2015-05-20

Locations

2 sites across 1 country: Denmark